Many modern mobile devices (e.g., a smart phone, tablet computer, wearable computer) include one or more radio frequency receivers, transmitters, or transceivers that allow one-way or two-way communications with other devices. For example, a mobile device can use a transceiver to communicate with a server on the Internet via a base station of a wireless network. In another example, a mobile device can include a receiver to receive low powered RF signals from devices such as RF beacons.